We begin with an electrifying day at the supreme court, the nine justices wrestling again with the question of same-sex marriage, but this time, they were challenged by an 83-year-old woman who brought them her 40-year-old love story. She received a huge welcome when she emerged from the supreme court saying, it's time to take a stand for marriage equality. And abc's terry moran was there. It's a classic american story. Sometimes the big cases come to the supreme court out of conflicts between the states or battles between the branches of government and sometimes one american walks up these steps seeking justice. That's what happened today. Reporter:83 and radiant. Edid I windsor had her day in court. And what a day it was for her. THIS WOMAN, BORN IN THE 1920s Has become a folk hero to countless. You are talking freely, I'd have been hiding in a closet ten years ago. Reporter: Her case arises from the love her life. Edid I worked at ibm. Leah was a therapist. Edid I who lives on a fixed income was hit with $362,000 in estate taxes, that no straight widow would pay. A federal government refused to recognize their marriage under defense of marriage act. Which defines marriage under federal law as the union of one man, affecting taxes, social security, military survivor benefits. Today in court, ruth ginsburg said it seems like a second-class system for gay couples. There's two kinds of mage. The full marriage and then the sort of marriage. Reporter: This equal sign became an overnight symbol of solidarity with gay couples. Since president obama said the 1996 law is unconstitutional, house republican leaders are defending it, their lawyer telling the court that all congress was doing was setting one federal standard for marriage, but olena kagan challenged that claim, suggesting something darker may have been at work. I'm going to quote from the house report here. Is that congress decided to reflect and honor a collective moral judgement and to express moral disapproval of homosexuality. Is that what happened in 1996? Reporter: But for millions of americanss, same-sex marriage is about bedrock beliefs. We're not motivated by hit. Or bigotry. We just believe that when the guarder of the bible created the institution, he didn't get our advice on it, he defined it and I really believe he got it right. Today is like a spectacular event for me. It's a lifetime kind of event. And I know it's the spirit of my late spouse is right here watching and listening and would be very proud and happy where we've come to. Reporter: Edid I was in the front row, she had headphones on, she's hard of hearing. She was taking her head when she was concerned and looking just as confused as the rest of us at other times.

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